A. Field
The present invention relates to a method for the simultaneous operation of two interfaces of a portable data carrier as well as such a data carrier, in particular a chip card, a secure multimedia card, a mobile radio card or the like.
B. Technological Background
Present developments in the field of portable data carriers, such as e.g. chip cards and the like, for more flexible application possibilities use a plurality of physically independent interfaces. In particular, portable data carriers can be provided with a conventional contact-type interface as well as an additional contactless interface, e.g. an antenna device for a radio link. The actual data communication then is carried out with the help of respective contact-type communications protocols (in the field of chip cards and mobile radio communications e.g. T=0, T=1) and/or contactless communications protocols (e.g. T=CL) with an external communication unit, with which the data carrier is in a communication connection.
Both, the operating systems and control systems available for portable data carriers having a contact-type and a contactless interface and the data communication modes presently supported by the multiple read/write units and communication units, however, exclusively admit only one data communication at a time either via the contact-type or via the contactless interface. But this is disadvantageous in situations, in which during a data communication via one of the two interfaces, via the other interface there starts a further data communication, which is not repeatable at a later point in time. Such a scenario is given with a portable data carrier formed as a mobile radio card, for example, when via the contact-type interface there is made a mobile phone call and meanwhile via the contactless interface a payment transaction, e.g. in public transport, is to be handled. For other types of portable data carriers other scenarios are thinkable respectively.
An obvious solution of this problem is to install a real-time multitasking operating system on the portable data carrier, in order to realize a simultaneous data communication via the two interfaces as concurrent, virtually parallel processes. At present, however, this solution is not realistic in view of the limited resources of portable data carriers and in many cases also not required for the normal use of such data carriers.
U.S. Pat. No. 6,105,874 discloses a portable data carrier with a contact-type and a contactless interface, which switches between the two interfaces with the help of an OR logic. But when the two interfaces are active at the same time the OR operation leads to data losses. U.S. Pat. No. 6,045,043 discloses a double interface apparatus, with which a contactless data communication is started, as soon as a magnetic field is present at the contactless interface, independent of the respective state of the contact-type interface. Such preferential treatment of the contactless interface, however, leads to disadvantages with respect to the stability of contact-type data communications.
Therefore, it is an object of the present invention, that a contact-type and a contactless interface of a portable data carrier can be simultaneously and reliably operated.